Stretching my ears

Hey guys so I love having piercings and I started stretching my ears a while ago and I’ve got up to 8mm but I tried to go to 10mm which is the next size up and it’s really hurting. Anyone know how to do it without hurting. I’ve left them in half way because that’s where it doesn’t hurt but is still slightly bigger. Do I keep pushing it through gradually? Or is it meant to hurt?